TW201925847A - Cross section processing observation method and charged particle beam apparatus - Google Patents

Abstract

Provided is a cross-section processing observation method capable of easily and accurately forming a cross-section used to observe a sample's inside, and a cross-section processing observation apparatus for cross-section processing. The method includes a design data acquisition step acquiring design data of a three-dimensional structure of a sample having three-dimensional structure, a moving step moving the sample based on coordinate information of the design data, a surface observation step acquiring an observation image of a surface of the sample, a cross-section forming step irradiating the sample's surface with an ion beam to form a cross-section of the three-dimensional structure, a cross-section observation step acquiring an observation image of the sample's cross-section, and a display step displaying image data, among pieces of the design data, of surface and cross section corresponding to respective locations of the surface and the cross section.

Description

Profile processing observation method, charged particle beam device

The present invention relates to a cross-sectional processing observation method for processing a cross section for observation of a sample when observing a sample having a three-dimensional solid structure such as a semiconductor device, and a charged particle beam device for performing cross-sectional processing.

For example, when observing the inside of a sample having a three-dimensional anatomical structure such as a semiconductor device, the observation is performed by using a focused ion beam (FIB) to break the sample to form an arbitrary observation of the three-dimensional solid structure. Using a section, an electron microscope was used to observe the section. In such a cross section for observation, for example, when it is desired to observe a defective portion of the sample, the position is determined by a defect inspection device or the like, and the cross-sectional processing is performed based on the acquired position information.

A technique for performing processing positioning based on the CAD data of the sample and the observation image on the surface of the sample is disclosed (for example, refer to Patent Document 1). By associating the CAD data of the sample with the secondary charged particle image, the processing and positioning of the charged particle beam device can be performed.

Further, regarding the FIB-SEM apparatus, a technique is disclosed in which the cross-sectional processing and observation are repeated, and the processing end point is detected based on the cross-sectional image (for example, refer to Patent Document 2). The FIB processing end point can be detected by measuring the distance between the ends of the special structures in the image by SEM observation after FIB processing.

[Previous Technical Literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-155984
[Patent Document 2] Japanese Patent Laid-Open No. Hei 11-273613

[Questions to be solved by the invention]

In Patent Document 1 described above, the positional relationship between the CAD data and the like and the surface of the sample is correlated. However, since the observation target inside the sample cannot be directly observed, it is impossible to correlate in the depth direction of the sample. Therefore, it is possible to process the observation object or cut out a sample piece that does not include the observation object.

Further, in Patent Document 2, if the observation target is smaller than the slice width, the observation target may not be subjected to SEM observation, and thus the end point detection cannot be accurately performed. Therefore, it is possible to process the observation object.

The present invention has been made in view of the above-described problems, and an object of the invention is to provide a cross-sectional processing observation method capable of easily and accurately forming an observation cross section for observing the inside of a sample, and a charged particle beam device for performing cross-sectional processing.

[Means for solving the problem]

In order to solve the above problems, several aspects of the present invention provide the following cross-sectional processing observation method and charged particle beam apparatus.
In other words, the cross-sectional processing observation method of the present invention includes a design data acquisition step of obtaining design data of the three-dimensional solid structure of a sample having a three-dimensional solid structure, and a moving step according to the above The coordinate information of the design data moves the sample; the surface observation step is an observation image of the surface of the sample; and the cross-section forming step of irradiating the surface of the sample with an ion beam to form a cross section of the three-dimensional solid structure a cross-sectional observation process for obtaining an observation image of the cross-section; and a display process for displaying image data of a surface and a cross-section of a position corresponding to the surface and the cross-section in the design data.

According to the present invention, when the sample is processed by moving the breaking position, the image of the observation image of the cross section and the image data of the cross section are transmitted, and it is not necessary to provide a processing mark or the like in advance, and the sample can be accurately and accurately removed until the sample is reached. The observation target section can easily process the sample exposed by the observation target section.

Furthermore, the present invention may further include a new section forming step of slicing the cross section according to a predetermined slice width to form a new cross section, and a refreshing process for the aforementioned design data. The image data of the section of the new section is updated at a considerable position.

Furthermore, the present invention may further include a positioning step of performing positioning of sampling of the sample based on the design data, and a comparison step of observing the cross section of the sample in the cross-sectional forming step. And comparing the image data of the cross section at the position corresponding to the observation image of the cross section in the design data described above.

A charged particle beam device according to the present invention includes: a charged particle beam lens barrel that irradiates a charged particle beam with a sample having a three-dimensional three-dimensional structure; and a memory portion that memorizes design data of the three-dimensional three-dimensional structure; a secondary particle detector that detects secondary particles generated from a surface and a cross section of the sample by irradiating the charged particle beam; and an image forming portion that forms a surface of the sample according to a detection signal of the secondary particle detector The observation image of the cross section; and the display control unit for displaying the image data of the surface and the cross section at the position corresponding to the surface and the cross section in the design data.

Furthermore, the present invention may further include: an update unit that is in contact with a slicing process of the sample due to the irradiation of the charged particle beam, and a cross section of a position corresponding to a cross section newly exposed by slicing in the design data. The image data is updated.

Furthermore, the present invention may further include a comparison unit that compares the observed image of the sample with the image data at a position corresponding to the cross-section in the design data.

[Effect of the invention]

According to the present invention, a cross-sectional processing observation method and a charged particle beam device capable of easily and accurately forming an observation cross section for observing the inside of a sample are provided.

Hereinafter, a cross-sectional processing observation method and a charged particle beam apparatus of the present invention will be described with reference to the accompanying drawings. The embodiments described below are specifically described in order to better understand the contents of the invention, and the invention is not limited thereto unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easy to understand, the parts as the main parts may be enlarged for the sake of convenience, and the dimensional ratios of the respective constituent elements may not necessarily be actual. the same.

(section processing device)
Fig. 1 is a configuration diagram showing a cross-section processing apparatus having a charged particle beam device according to an embodiment of the present invention.
The cross-section processing apparatus 10 according to the embodiment of the present invention includes a charged particle beam device 10a. The charged particle beam device 10a includes a sample chamber 11 that can be maintained in a vacuum state, a stage 12 that can fix the sample S inside the sample chamber 11, and a stage drive mechanism 13 that is attached to the stage. 12 to drive.

The charged particle beam device 10a further includes a focused ion beam optical system (focusing ion beam barrel) 14 that illuminates the focused ion beam (FIB) to an irradiation target in a predetermined irradiation area (i.e., scanning range) inside the sample chamber 11. ). Further, the charged particle beam device 10a further includes an electron beam optical system (charged particle beam column) 15 that irradiates an electron beam (EB) to an irradiation object in a predetermined irradiation region inside the sample chamber 11.

The charged particle beam device 10a further includes a detector (secondary particle detector) 16 that detects secondary charged particles (secondary electrons, secondary ions) generated from the irradiated object by irradiation of the focused ion beam or the electron beam. R. On the output side of the detector (secondary particle detector) 16, an image forming portion 25 that forms a surface of the sample and an observation image of the cross section based on the detection signal of the detector 16 is provided. The charged particle beam device 10a has a gas supply portion 17 that supplies a gas G to the surface of the object to be irradiated. Specifically, the gas supply unit 17 is a gas nozzle 17a or the like.

The charged particle beam device 10a includes a needle 18 that takes out a small sample piece Q (for example, a sample piece for TEM observation) from a sample S fixed to the stage 12, holds the sample piece Q, and transfers it to the sample piece to be held. The needle P; and a needle drive mechanism 19 that drives the needle 18 to carry the sample piece Q. The needle 18 and the needle driving mechanism 19 are sometimes collectively referred to as a sample piece transferring unit.

The charged particle beam device 10a includes a display device 20, a computer 21, and an input device 22 that displays image data or the like based on the secondary charged particles R detected by the detector 16.

The charged particle beam device 10a of the present embodiment can perform imaging of the irradiated portion and various processing by sputtering (such as drilling, trimming, etc.) by irradiating the focused ion beam while scanning the surface of the irradiated object. And formation of a deposited film, and the like. The charged particle beam device 10a can perform processing for forming a sample piece Q (for example, a sheet sample, a needle sample, etc.) for transmission observation of a transmission electron microscope from the sample S or an analysis sample piece for electron beam use.

The charged particle beam device 10a can also perform processing for causing the sample piece Q to be transferred to the sample holder P to be a film having a desired thickness (for example, 5 nm to 100 nm) suitable for transmission observation using a transmission electron microscope. The charged particle beam device 10a can perform observation of the surface of the irradiated object by irradiating the focused ion beam or the electron beam on the surface of the irradiated object such as the sample piece Q and the needle 18 while scanning.

The sample chamber 11 is configured to be exhausted by an exhaust device (not shown) until the inside thereof is in a desired vacuum state and can maintain a desired vacuum state.
The stage 12 holds the sample S. The stage 12 has a holder fixing table 12a that holds the sample holder P. The holder fixing table 12a may have a structure in which a plurality of sample holders P can be mounted.

The stage drive mechanism 13 is housed in the sample chamber 11 in a state of being connected to the stage 12, and the stage 12 is displaced relative to a predetermined axis based on a control signal output from the computer 21. The stage driving mechanism 13 is provided with a moving mechanism 13a that moves at least the stage 12 in parallel along the X-axis and the Y-axis which are parallel to the horizontal plane and perpendicular to each other, and the Z-axis which is perpendicular to the X-axis and the Y-axis. . The stage driving mechanism 13 further includes a tilting mechanism 13b that tilts the stage 12 about the X-axis or the Y-axis, and a rotating mechanism 13c that rotates the stage 12 about the Z-axis.

The focused ion beam optical system (focusing beam barrel) 14 faces the stage 12 with a beam emitting portion (not shown) in the vertical direction of the stage 12 in the irradiation region inside the sample chamber 11 and The optical axis is fixed to the sample chamber 11 in parallel with the vertical direction. Thereby, the focused ion beam can be irradiated to the irradiation target such as the sample S fixed to the stage 12, the sample piece Q, and the needle 18 existing in the irradiation area from the upper side in the vertical direction.

The focused ion beam optical system 14 includes an ion source 14a that generates ions, and an ion optical system 14b that converges and deflects ions extracted from the ion source 14a. The ion source 14a and the ion optical system 14b are controlled based on a control signal output from the computer 21, and the computer 21 controls the irradiation position of the focused ion beam, the irradiation conditions, and the like.

The ion source 14a is, for example, a liquid metal ion source using a liquid gallium or the like, a plasma ion source, a gas electric field ionization type ion source, or the like. The ion optical system 14b includes, for example, a first electrostatic lens such as a condensing lens, an electrostatic deflector, and a second electrostatic lens such as an objective lens.

The electron beam optical system (charged particle beam barrel) 15 inclines the beam emitting portion (not shown) within the sample chamber 11 by a predetermined angle (for example, 60°) with respect to the vertical direction of the stage 12 in the irradiation region. The inclined direction faces the stage 12, and the optical axis is fixed to the sample chamber 11 so as to be parallel to the oblique direction. Thereby, the electron beam can be irradiated to the object to be irradiated, such as the sample S fixed to the stage 12, the sample piece Q, and the needle 18 existing in the irradiation area, from the upper side in the oblique direction.

The electron beam optical system 15 includes an electron source 15a that generates electrons, and an electron optical system 15b that converges and deflects electrons emitted from the electron source 15a. The electron source 15a and the electron optical system 15b are controlled based on the control signal output from the computer 21, and the computer 21 controls the irradiation position of the electron beam, the irradiation conditions, and the like. The electro-optical system 15b has, for example, an electromagnetic lens, a deflector, and the like.

Alternatively, the arrangement of the electron beam optical system 15 and the focused ion beam optical system 14 may be reversed, the electron beam optical system 15 may be disposed in the vertical direction, and the focused ion beam optical system 14 may be disposed at a predetermined angle with respect to the vertical direction. The direction of the tilt.

The detector 16 detects the intensity of secondary charged particles (secondary electrons and secondary ions) R radiated from the irradiated object when the focused ion beam or the electron beam is irradiated to the irradiation target such as the sample S and the needle 18 (ie, secondary charging) The amount of particles is), and the information of the detected amount of the secondary charged particles R is output. The detector 16 is fixed to the sample chamber 11 so as to be disposed inside the sample chamber 11 at a position where the amount of the secondary charged particles R can be detected (for example, at a position obliquely above the irradiation object such as the sample S in the irradiation region). .

The gas supply unit 17 is fixed to the sample chamber 11 and has a gas injection unit (also referred to as a nozzle) inside the sample chamber 11 , and the gas supply unit is disposed such that the gas injection unit faces the stage 12 . The gas supply unit 17 can supply an etching gas, a deposition gas, and the like to the sample S for selectively promoting etching of the sample S by the focused ion beam according to the material of the sample S, the deposition gas. It is used to form a deposited film based on a deposit such as a metal or an insulator on the surface of the sample S. For example, an etching gas such as cesium fluoride for the Si-based sample S and water for the organic sample S is supplied to the sample S while irradiating the focused ion beam to selectively promote etching. Further, for example, by supplying a deposition gas containing platinum, carbon, or tungsten to the sample S while irradiating the focused ion beam, solid components decomposed from the deposition gas can be deposited (deposited) on the surface of the sample S. . Specific examples of the gas for deposition include phenanthrene or naphthalene as a gas containing carbon, trimethyl, ethylcyclopentadienyl, platinum, etc. as a gas containing platinum, and a gas containing tungsten. Has hexacarbonyl tungsten and the like. Further, depending on the supply gas, etching or deposition can also be performed by irradiating the electron beam.

The needle drive mechanism 19 is housed inside the sample chamber 11 in a state of being connected to the needle 18, and the needle 18 is displaced in accordance with a control signal output from the computer 21. The needle drive mechanism 19 is integrally provided with the stage 12. For example, when the stage 12 is rotated about the tilt axis (that is, the X axis or the Y axis) by the tilt mechanism 13b, the needle drive mechanism integrally moves with the stage 12. The needle drive mechanism 19 includes a moving mechanism (not shown) that moves the needle 18 in parallel along each axis of the three-dimensional coordinate axis, and a rotation mechanism (not shown) that surrounds the needle 18 around the needle 18. The center axis rotates. Further, the three-dimensional coordinate axis is a vertical three-axis coordinate system having a two-dimensional coordinate axis parallel to the surface of the stage 12, independent of the vertical three-axis coordinate system of the sample stage, and is inclined on the surface of the stage 12, In the case of a rotating state, the coordinate system is tilted and rotated.

The computer 21 is disposed outside the sample chamber 11 and includes a display device 20, a display control unit 23, a storage unit 21a, a comparison unit 21b, and an update unit 21c. The display control unit controls the display device 20. Further, an input device 22 such as a mouse and a keyboard that outputs a signal corresponding to the input operation of the operator is connected. Such a computer 21 collectively controls the operation of the charged particle beam device 10a based on a signal output from the input device 22 or a signal generated by a predetermined automatic operation control process.

The display control unit 23 is configured by an IC wafer or the like, and has a function of causing the display device 20 to display the design data of the three-dimensional solid structure formed inside the sample S in comparison with the surface and the cross section in the cross-sectional processing observation method to be described later. Image information of the location.
The memory unit 21a is constituted by, for example, a memory or a hard disk, and stores design data of a three-dimensional solid structure in a cross-sectional processing observation method to be described later.
Further, the comparison unit 21b is configured by, for example, a CPU, a cache memory, or the like, and performs image processing at a position corresponding to the processing profile in the observation image of the sample and the design data of the three-dimensional solid structure in a cross-sectional processing observation method to be described later. Comparison.

In addition, the update unit 21c is configured by, for example, a CPU and a memory. In the cross-sectional processing observation method to be described later, for example, a three-dimensional solid formed in the inside of the sample S in conjunction with the slice processing of the sample by electron beam (EB) irradiation is used. In the design data of the structure, the image data of the section corresponding to the newly exposed section in the slicing process is updated.
The comparison of the observation images of such samples with the image data and the determination of the coincidence and inconsistency are performed by the image analysis software executed by the computer 21.

Further, the computer 21 converts the detection amount of the secondary charged particles R detected by the detector 16 while scanning the irradiation position of the charged particle beam into a luminance signal corresponding to the irradiation position, based on the detection of the secondary charged particles R. The two-dimensional position distribution of the amount generates image data showing the shape of the illuminated object.

The display device 20 displays a designed cross-sectional image on an arbitrary cross section of the design data of the three-dimensional solid structure and an actual cross-sectional image of the sample S based on the secondary charged particles R generated from the irradiated object. Further, a screen for performing operations such as enlarging, reducing, moving, and rotating such a cross-sectional image is displayed. The computer 21 causes the display device 20 to display a screen for performing various settings such as mode selection and processing setting in the sequence control.

Further, the charged particle beam device 10a of the present invention includes at least an electron beam optical system (charged particle beam column) 15, a memory portion 21a, a detector (secondary particle detector) 16, and image formation as long as it has the above-described respective configurations. The unit 25 and the display control unit 23 are only required.

(Section processing observation method: pre-process (sampling method))
Next, a cross-sectional processing observation method of the present invention using the above-described cross-section processing apparatus will be described.
In the following embodiment, the sample piece Q including the target observation target cross section is cut out from the sample S of the block having the three-dimensional anatomical structure inside the semiconductor circuit or the like by microsampling (previous step). Further, the sample piece is removed along the machine direction to process a cross section of the observation target (post-process).
Fig. 2 is a flow chart showing in stages the pre-process of the cross-sectional processing observation method of the present invention. First, in the first step, an instruction is made via the input device 22 of the computer 21 to acquire design data of the three-dimensional solid structure formed in the sample S, and the memory portion 21a of the computer 21 memorizes the design data of the three-dimensional solid structure ( S1: Design data acquisition process). For example, in the case of a semiconductor circuit, the design data may be circuit design data showing a three-dimensional structure of the circuit including a coordinate value.

Next, at least two of the three faces of the rectangular sample S (hereinafter, the upper surface (XY plane), the front surface (XZ plane), and the side surface (YZ plane) are made into three planes) (preferably three faces) move (S2: moving process). The coordinates of the stage 12 during the movement include the design data of the three-dimensional solid structure formed in the sample S, the defect position information included in the sample S based on the defect inspection device, and the like. Further, the stage 12 can be moved based on various positional information other than the above.

Next, the sample S is irradiated with the electron beam EB from the electron beam optical system 15 at the position of the stage 12 after the movement. Then, the secondary charged particle R generated from the sample S is detected by the detector 16, and the SEM image of the sample S is obtained by the computer 21 (S3: surface observation step). When the SEM image of the sample S is obtained, at least two of the above three faces of the sample S are used, for example, the surface and the cross section of the sample S. Further, it is preferable to obtain an SEM image of all three faces of the sample S.

Next, a small area including the observation target section is determined based on the design data of the three-dimensional solid structure of the sample S (S4: positioning process). Then, the coordinates (coordinates of the outline) of the observation target section are selected from the design data of the three-dimensional solid structure, for example, and input to the computer 21.

The computer 21 operates the focused ion beam optical system 14 to face the sample S on the stage 12, and irradiates the focused ion beam FIB based on the input coordinate data to form an observation target of the three-dimensional solid structure formed in the sample S. Section (S5: section forming process).

Then, the electron beam EB is irradiated from the electron beam optical system 15 to the observation target cross section of the three-dimensional solid structure formed through the cross-section forming step S5. Then, the secondary charged particle R generated from the observation target cross section of the three-dimensional solid structure is detected by the detector 16, and the SEM image of the observation target cross section of the three-dimensional solid structure is obtained by the computer 21 (S6: cross-sectional observation step).

Next, the SEM image of the cross section of each of the two faces to the three faces of the sample S obtained by the cross-sectional observation step S6 and the design data of the three-dimensional three-dimensional structure corresponding to the SEM image are displayed on the display device 20 Image (S7: Display process).

As an example of such a display process S7, as shown in FIG. 4(a), the upper surface SEM image Sxy01, the front surface SEM image Sxz01, and the side surface SEM image Syz01 of the sample S are respectively displayed on the display device 20. Further, on the display device 20, the corresponding upper surface image Dxy01, the front surface image Dxz01, and the side surface image Dyz01 of the design data are respectively displayed.

Then, as shown in FIG. 4(b), the SEM image of each of the three faces of the sample S and the image of the three faces of the design data corresponding to the SEM image are superimposed. Then, as shown in FIG. 4(c), the sizes of the two types of images, that is, the display magnifications are matched, and the upper surface image Exy01, the front surface image Exz01, and the side surface image Eyz01 (S5) after the magnification adjustment are displayed. Further, regarding the magnification adjustment, the size of the image on the three faces of the design data can be made to match the size of the SEM image of the sample S, and the size of the SEM image of the sample S and the three faces of the design data can be reversed. The size of the image is the same. As a result, the SEM image (cross section) of the processed surface of the sample piece Q cut out from the sample S in the subsequent step and the image (cross section) of the portion corresponding to the design data are on the same scale on the screen of the display device 20. Therefore, it is possible to determine the consistency and inconsistency of the images of each other.

According to the pre-process (sampling method) of the cross-sectional processing observation method of the present invention, the surface of the sample S is produced by the focused ion beam FIB, and the cross-section is formed by the focused ion beam FIB, thereby obtaining an SEM image of the observation target cross-section. The observation image of the observation target section can be obtained without moving the stage 12, and positional displacement does not occur.

(Profile processing method: post-process (section processing method))
Fig. 3 is a flow chart showing the post-process of the cross-sectional processing observation method of the present invention in stages. The computer 21 operates the focused ion beam optical system 14 to face the sample S on the stage 12, and irradiates the focused ion beam FIB based on the input coordinate data to form a sample piece as a small area of the sample S (S11: sample formation) Process). More specifically, based on the input coordinate data, the computer 21 operates the focused ion beam optical system 14 to illuminate the focused ion beam FIB toward the sample S. As a result, as shown in FIG. 5, in the sample S, the periphery of the observation target cross section is etched to form a sample piece Q including the observation target cross section. The needle driving mechanism 19 is driven to adhere the needle 18 to the formed sample piece Q, thereby taking out the sample piece Q. Then, the sample piece Q is fixed to the sample piece holder P.

Next, the formed sample piece (sample) Q is subjected to cross-sectional processing to expose the observation target cross section. In the case of the subsequent step, as an example of the three-dimensional three-dimensional structure, it is assumed that the linear wirings extending in the X direction, the Y direction, and the Z direction are combined as shown in the three views of FIG. 6 . Simple model. The three-dimensional three-dimensional structure is configured to have a plurality of wirings Cx extending in the X direction, a plurality of wirings Cy extending in the Y direction, and Z wirings (contacts) Cz that connect the X wirings and the Y wirings. In the following processing example, the sample piece (sample) Q is cut at a predetermined interval from the one surface of the three-dimensional solid structure in the Y direction in which the machining direction is written, and the cross section Ft is exposed as the observation target section. .
In addition, although an example in which three surfaces of a three-dimensional three-dimensional structure are observed and processed is shown here, it is also possible to observe and process any two surfaces of a three-dimensional three-dimensional structure.

FIG. 7 is a schematic diagram showing an example of a video displayed on a display device.
First, the focused ion beam FIB is irradiated from the XZ plane of the sample piece (sample) Q in the Z direction, and the sample piece Q is removed in the Y direction (cross-sectional processing direction) (S11: sample piece forming step). Then, the electron beam EB (a new cross-section forming step of forming a new cross section by the slicing process) is irradiated from the electron beam optical system 15 toward the processing section of the exposed F1 position, and the processed cross-sectional image at the F1 position of the sample piece Q is obtained (S12). : Processing section image acquisition process).

Then, on the display device 20, the three-dimensional design data of the three-dimensional solid structure at the F1 position based on the design data of the three-dimensional solid structure, the observation target cross-sectional image based on the design data of the predetermined observation target, and the F1 are displayed in parallel on the display device 20. The actual machined profile image of the position (see Figure 7(a)). Then, the comparing unit 21b of the computer 21 compares the actual processed sectional image at the F1 position with the observed target sectional image based on the design data (S13: comparison step).

Further, when the actual processed cross-sectional image is different from the observation target cross-sectional image based on the design data, the focused ion beam FIB is again irradiated from the XZ plane of the sample piece (sample) Q along the Z direction, and the predetermined sample is removed from the sample piece Q. Amount (S11: sample piece forming step).
In the state of FIG. 7(a), when the Y direction is at the position of F1, the actual processed sectional image is different from the observation target sectional image based on the design data, and therefore it is determined that the cross-sectional processing of the sample piece Q does not reach the observation target section. , thereby irradiating the focused ion beam FIB again to remove the sample piece Q by a prescribed amount (S11)

Then, the focused ion beam FIB is irradiated from the XZ plane of the sample piece (sample) Q in the Z direction, and the sample piece Q is removed in the Y direction (cross-sectional processing direction) (S11: sample piece forming step). Then, the electron beam EB is irradiated from the electron beam optical system 15 toward the processed cross section at the F2 position, and the processed cross-sectional image at the F2 position of the sample piece Q is obtained (S12: processed cross-sectional image obtaining step).
Then, as shown in FIG. 7(b), the comparing unit 21b of the computer 21 compares the actual processed sectional image at the F2 position with the observed target sectional image based on the design data (comparison step S13). Further, the three-dimensional image of the design data of the three-dimensional solid structure is updated in accordance with the progress of the processing.

By performing such a process, the data is sequentially deleted from the display corresponding to the portion processed by the focused ion beam FIB. Regarding the update of the image data, the data is deleted from the display by processing in accordance with a predetermined slice width. With this configuration, it is possible to confirm the machining condition in the design data image, and to confirm the actual machining condition in the observation image based on the SEM image. Therefore, the machining end point can be accurately detected without excessive machining (overcutting).

For example, in FIG. 7(b), when the Y direction is at the position F2, the actual processed cross-sectional image is different from the observation target cross-sectional image based on the design data. Therefore, it is determined that the cross-sectional processing of the sample piece Q does not reach the observation target cross-section. Then, the focused ion beam FIB is irradiated again to remove the sample piece Q by a predetermined amount (S11: sample piece forming step).

Then, the focused ion beam FIB is irradiated from the X-Z plane of the sample piece (sample) Q in the Z direction, and the sample piece Q is removed in the Y direction (cross-sectional processing direction) (S11: sample piece forming step). Then, the electron beam EB is irradiated from the electron beam optical system 15 toward the processing cross section at the exposed F3 position, and the processed cross-sectional image at the F3 position of the sample piece Q is obtained (S12: processed cross-sectional image obtaining step).

Then, as shown in FIG. 7(c), the comparing unit 21b of the computer 21 compares the actual processed sectional image at the F3 position with the observation target sectional image based on the design data (S13: comparison step). Further, the three-dimensional image of the design data of the three-dimensional solid structure is updated in accordance with the progress of the processing.

As shown in Fig. 7(c), when the Y-direction is at the position of F3, the actual processed cross-sectional image is different from the observation target cross-sectional image based on the design data. Therefore, it is determined that the cross-sectional processing of the sample piece Q does not reach the observation target cross-section, and is irradiated again. The ion beam FIB is focused to remove the sample piece Q by a predetermined amount (S11: sample piece forming step).

Then, the focused ion beam FIB is irradiated from the XZ plane of the sample piece (sample) Q in the Z direction, and the sample piece Q is removed in the Y direction (cross-sectional processing direction) (S11: sample piece forming step). Then, the electron beam EB is irradiated from the electron beam optical system 15 toward the processing cross section at the exposed F4 position, and the processed cross-sectional image at the F4 position of the sample piece Q is obtained (S12: processed cross-sectional image obtaining step).
Then, as shown in FIG. 7(d), the comparing unit 21b of the computer 21 compares the actual processed sectional image at the F4 position with the observation target sectional image based on the design data (S13: comparison step). Further, the three-dimensional image of the design data of the three-dimensional solid structure is updated in accordance with the progress of the processing.

In the state of FIG. 7(d), the actual processed section image when the Y direction is at the position of F4 coincides with the observation target section image based on the design data. Thus, the actual machining sectional image when the computer 21 determines that the Y direction is at the position F4 based on the comparison result of the comparison unit 21b is the observation target cross section (cross section) Ft, and this position is used as the machining end point (S14: machining end processing step) ).

In this way, each time the focused ion beam FIB is irradiated to remove the sample piece Q by a predetermined amount, the actual processed sectional image and the observation target sectional image based on the design data are repeatedly compared, thereby eliminating the need to provide a processing mark or the like in advance. The sample piece Q exposed to the observation target cross section can be easily processed by a simple process and automatically and automatically removed until the observation target cross section of the sample piece (sample) Q is reached.

Further, in the above-described comparison step S13, in addition to comparing the actual processed cross-sectional image with the observation target cross-sectional image based on the design data, the coordinate values can be compared. For example, in the comparison step S13, the coordinates on the design data corresponding to the current machining profile based on the design data and the actual coordinates on the sample piece (sample) Q of the processed section image are compared to determine the actual coordinate value. Whether the coordinates on the design data corresponding to the observation target profile are reached.
In addition, as long as the size of the image of the three faces of the design material matches the size of the SEM image of the sample S in the previous process, it is possible to accurately determine the coincidence and the inconsistency on the same scale.

Thereby, the machining accuracy can be further improved as compared with the case of comparing only the cross-sectional image. For example, if the method of reducing the amount of removal of the sample piece Q by the focused ion beam FIB is controlled in such a manner that the actual coordinate value becomes close to the coordinate on the design data corresponding to the observation target profile, the observation can be more accurately obtained. The observation section exposed by the target section does not cut the sample piece (sample) Q to a position deeper than the observation target profile.

In the above-described embodiment, an example of forming a sample piece for TEM observation is shown as a sample (sample piece). Alternatively, for example, a three-dimensional atom probe as a needle sample can be formed (3). Used when Dimensional Atom Probe).
In other words, when a three-dimensional atom probe is formed, in the above-described pre-step (sampling method) of the present invention, a sample piece including an observation target of a three-dimensional anatomical structure is cut out. Then, in the post-process (cross-section processing method), the sample is processed using the focused ion beam FIB so that the sample piece becomes an acicular sample (atomic probe sample) including the observation target of the three-dimensional anatomical structure.
In such a three-dimensional atom probe, for example, a positive voltage of about 10 kV is applied to a tapered needle sample having a tip end diameter of about 100 nm, so that the tip end of the probe becomes a high electric field, and the electric field evaporates by the electric field evaporation phenomenon. The atomic arrangement is determined using a 2-dimensional detector. In addition, it is also possible to distinguish the ion species from the flight time before reaching the detector. By continuously detecting such individually detected ions in the depth direction and arranging the ions in the detected order, the element information and the three-dimensional structure of the sample can be analyzed at the atomic level.

Further, in the comparison step S13, the operator can visually compare the actual processed cross-sectional image with the observation target cross-sectional image based on the design data without depending on the image comparison software or the like.
Further, in the above-described embodiment, as an example of the pre-process, the sample piece Q is microsampled from the sample S, and the sample piece Q sampled by the cross-sectional image comparison is processed. However, the sample piece Q may be processed as follows. Structure: The pre-process and the post-process are not specifically distinguished, and the observation target cross section is exposed by the removal of the focused ion beam FIB and the cross-sectional image comparison by repeating the sample S of the block.

The embodiments of the present invention have been described above, but such embodiments are merely illustrative and are not intended to limit the scope of the invention. The embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. The embodiments and the modifications thereof are included in the scope of the invention and the scope of the invention as set forth in the appended claims.

10‧‧‧section processing device

10a‧‧‧Powered particle beam device

11‧‧‧Test room

12‧‧‧Moving station (sample carrier)

13‧‧‧stage drive mechanism

14‧‧‧Focused ion beam optical system

15‧‧‧Electron beam optical system (charged particle beam tube)

16‧‧‧Detector

17‧‧‧Gas Supply Department

18‧‧‧ needle

19‧‧‧needle drive mechanism

20‧‧‧ display device

21‧‧‧ computer

22‧‧‧ Input device

P‧‧‧ sample holder

Q‧‧‧ sample material (sample)

R‧‧‧Second charged particles

S‧‧‧ samples

Fig. 1 is a schematic view showing a schematic configuration of a charged particle beam device according to an embodiment of the present invention.

Fig. 2 is a flow chart showing the pre-process of the cross-sectional processing observation method of the present invention in stages.

Fig. 3 is a flow chart showing the pre-process of the cross-sectional processing observation method of the present invention in stages.

FIG. 4 is an explanatory view showing magnification adjustment of a cross-sectional image. FIG.

Fig. 5 is a perspective view showing a state in which a sample piece is cut out from a sample.

Fig. 6 is a three-dimensional view showing an example of a three-dimensional three-dimensional structure.

FIG. 7 is an explanatory view showing a display example of a display device in the cross-sectional processing observation method of the present invention.

Claims (6)

A cross-section processing observation method has the following steps: a design data acquisition step of obtaining design data of the three-dimensional three-dimensional structure including a sample of a three-dimensional solid structure; a moving process of moving the sample according to coordinate information of the design data; a surface observation step of obtaining an observation image of a surface of the sample; a cross-section forming step of irradiating the surface of the sample with an ion beam to form a cross section of the three-dimensional solid structure; a cross-sectional observation process for obtaining an observation image of the cross-section; and A display process for displaying image data of a surface and a cross section of a position corresponding to the surface and the cross section in the design data. The cross-sectional processing observation method of claim 1, further comprising the following steps: a new section forming step of slicing the section according to a predetermined slice width to form a new section; The updating process updates the image data of the cross section at the position corresponding to the new profile in the design data. The cross-sectional processing observation method of claim 1 or 2, further comprising the following steps: a positioning process for positioning the sample of the aforementioned sample according to the aforementioned design data; In the cross-sectional forming step, the image of the cross-section of the sample and the image data of the cross-section at a position corresponding to the observed image of the cross-section in the design data are compared. A charged particle beam device having: a charged particle beam lens barrel that irradiates a charged particle beam with a sample having a three-dimensional three-dimensional structure; a memory unit that memorizes design data of the aforementioned three-dimensional three-dimensional structure; a secondary particle detector that detects secondary particles generated from a surface and a cross section of the sample by irradiating the charged particle beam; An image forming portion that forms an observation image of a surface and a cross section of the sample according to a detection signal of the secondary particle detector; A display control unit that displays image data of a surface and a cross section at a position corresponding to the surface and the cross section in the design data. The charged particle beam device of claim 4, further comprising: The update unit updates the image data of the cross section at the position corresponding to the cross section newly exposed by the slicing in the design data in conjunction with the slicing of the sample by the irradiation of the charged particle beam. The charged particle beam device of claim 4 or 5, wherein: The comparison unit compares the observation image of the sample with the image data at a position corresponding to the cross section in the design data.